Esp32 Multiband Digital Audio Processor

Features

• Web interface for control and configuration.
• Adjustment of the number of frequency bands in real time from 1 to 10.
• Graphic equalizer.
• Audio echo.
• Independent or synchronized adjustments for each audio compressor.
• Audio VU (low speed).
• Audio balance adjustment.
• Audio Pre-emphasis and Post-emphasis by software.
• Output audio peak protection system.
• Settings saving system with preset files.
• Circuit power supply directly from the USB port.
• Simplified scheme with a low number of electronic components.

Audio level and main

Compressor

Digital Audio Processor

Schematic (Digital Usb Input)

PCB Layout (Digital Usb Input)

Prototype (Digital Usb Input)

Schematic (PCM1802 ADC Input)

Tips

• The recommended input level is 15dB for PC volume control at 50%.
• To change a slider, first click on it and move it with the directional keys for better precision.
• The default access credentials are admin/admin.
• The WiFi AP credentials are DAP/123mudar.
• The Web interface IP is http://192.168.4.1

Dependencies

• https://github.com/junon10/STM32F411_USB_AUDIO_DAC
• https://github.com/junon10/yummyDSP
• https://github.com/junon10/ArduinoJson (old ArduinoJson 5.x)

Hardware

• 1 ESP32 MH ET LIVE WROOM DevKIT
• 1 STM32F411 BlackPill
• 1 PCM5102A DAC board

Notes

• This dynamic audio compression library is not perfect due to the insufficient speed of esp32, which makes it impossible to use real-time logarithm functions for more than two simultaneous frequency bands. In practice with this lib you get a good effect, but with a not very wide input dynamic range.

• There are other compressor variations, for example the unlinked MonoCompressor, which I will add to this code in the next updates.